DSCR

The measure

The ratio divides cash flow available for debt service in a period by interest and principal due in that period. A value of 1.0 means cash flow covers the payment exactly. Anything below it means the instalment has to come from a reserve or from shareholders.

What sits in the numerator is what decides the number. Available means cash flow after operating costs, insurance, ground rent, administration and tax, not revenue and not earnings before depreciation. Leaving items out of the numerator produces a figure that does not survive underwriting.

What lenders look for

German solar project financings typically fix a minimum ratio in the loan agreement and test it annually across the tenor. Requirements sit well above 1.0, because the headroom is the buffer for yield variance, price risk and outages. The specific requirement follows the revenue structure: an asset on a fixed tariff for 20 years supports tighter headroom than one whose revenue tracks market prices.

Alongside the annual ratio, lenders commonly look at the loan life coverage ratio across the whole facility. One measures the weakest single year, the other the shape of the whole.

What pushes it down

Four things, in this order: an optimistic yield forecast, understated operating costs, an amortisation profile that does not match the revenue profile, and a share of revenue with no contractual backing. The first two are modelling questions, the last two structural ones. A ratio that only clears the requirement after several rounds of adjusting assumptions is describing the model rather than the project.

In a lender's pack this is the number that gets recomputed first, which makes it the number whose derivation has to be complete. The value is not what decides the outcome; whether every item in the numerator is evidenced is: a yield study with a stated probability level, operating costs from a quote rather than a rule of thumb, ground rent from the signed lease.

In practice that means computing it early rather than at the end. It is the point at which the revenue structure and the financing structure either fit each other or do not, and both can be changed at the start of a project and not at the end.

Where the headroom is persistently too thin, the answer is rarely a different forecast. It is usually a different capital structure: more equity, a longer tenor, or an intermediate layer that makes the senior piece smaller.